Question [Q] restoring stock

Quick question, I achieved s-off the old fashion way by downgrading the bootloader, not revolutionary and I now have to flash the phone to unrooted stock and make sure it can receive OTA's.
I don't really care if the old s-off bootloader stays I'm on the 1.48.2000 bootloader with S-OFF

It seems to me that since the whole point of S-OFF is that it will now flash anything I can simply flash a stock RUU and be done with it, or will it cause issues.

I read in this thread that you could
But it's in the section for if you achieved s-off the revolutionary way.

Any thoughts? thanks.
Nexus 5 (Personal)
HTC First (Work)
Stock, Rooted
Retired Phones: AT&T Galaxy S4, Nexus 4, AT&T Galaxy S II,GSM Galaxy Nexus,HTC Rezound, Thunderbolt, Captivate, Focus (WP7), Blackberry Torch, iPhone3GS